7+ hour, 45+ min ago   (429+ words) Chariklo’s inner ring is getting denser. Its outer ring is fading. Both changes are happening at the same time — and, for the moment, nobody knows why. The finding matters beyond Chariklo itself. Ring systems around planets had already shown that…...

5+ day, 6+ hour ago   (374+ words) The spectrum added two more clues: broad, multi-peaked hydrogen emission combined with hydrogen absorption features, and tentative variability between two observations taken roughly a year apart. Black holes flicker as their feeding rates change. Stars don’t. The mechanism, once stated…...

6+ day, 5+ hour ago   (271+ words) The result covers two redshift windows, z ≈ 0.32 and z ≈ 0.44, corresponding to hydrogen variations measured across scales of several million light-years, roughly comparable to the separation between the Milky Way and Andromeda. It is a narrow slice of cosmic history. But…...

1+ week, 6+ hour ago   (770+ words) “In our simulations, the host galaxies alone caused the same kinds of irregularities that we observe in real stellar streams,” said Arpit Arora, a postdoctoral scholar at the UW Department of Astronomy and the study’s lead author. The team built…...

1+ week, 1+ day ago   (695+ words) The finding, in Nature Astronomy, comes from researchers at the Chinese Academy of Sciences and their international partners in the DESI collaboration. It is the largest direct measurement of cosmic hydrogen reserves ever made. It resolves a decades-old question about…...

1+ week, 2+ day ago   (501+ words) Two geometric storms on the same planet, at opposite poles, each locked to a different number of sides. Whatever is happening, it is not a fluke. “We’ve never seen anything quite like this in Saturn’s southern hemisphere,” Simon said. “This…...

1+ week, 5+ day ago   (385+ words) NASA’s IXPE has now changed that. By pointing its X-ray polarimetry instruments at magnetar 1E 1547.0-5408 for more than 140 hours, a team led by Rachael Stewart at George Washington University and Hoa Dinh Thi at Rice University found polarization values that nothing…...

1+ week, 6+ day ago   (210+ words) The telescope also carries a coronagraph instrument — a device that blocks starlight — enabling it to directly image exoplanets and planet-forming disks that would otherwise be lost in the glare of their host stars. That capability is separate from the wide-field…...

2+ week, 1+ day ago   (379+ words) They have now published their response in the same journal that ran the original challenge. The universe is still accelerating. The Nobel Prize is still justified. The mystery, though, is as deep as it has ever been. Dr. Phil Wiseman…...

2+ week, 4+ day ago   (477+ words) The Hubble tension adds a second pressure point. If the standard model is correct, both the early-universe and local measurements should converge on the same expansion rate. They do not. The most recent analysis using JWST-calibrated Cepheids confirms the local…...